RU2418748C2 - Reactor with packing - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to waste water treatment and can be used in chemical and biological industry. Biological treatment of liquid is carried out in reactor 100. Reactor 100 has packing layers 102, the first layer consisting of hollow elements 120 and the second consisting of porous carrier elements with 6-8 pores per centimetre. The stream of liquid is fed into the reactor 100 through a distributor 130. Gas is fed through a diffuser 138. The purified liquid comes out through an outlet 134.

EFFECT: invention enables to avoid excess penetration of the liquid through the reactor, increases degree of purity of the liquid.

10 cl, 2 tbl, 2 ex, 6 dwg

Description

Technical field

The present invention relates generally to reactors. More specifically, the present invention relates to layered reactors that can be used in chemical and biological processes.

BACKGROUND OF THE INVENTION

Stuffed reactors are commonly used in various processes in the chemical, pharmaceutical, fermentation industries and for wastewater treatment. In general, the packing contributes to an increase in the surface inside the reactor, which is reflected in the ratio of the surface to volume for the selected packing. Typically, the packing surface is that surface on which reaction promoters such as microbes can be attached in biological reactors or reaction promoters such as chemical catalysts in chemical reactors. Since a biological or chemical reaction usually depends on the contact of the reactants and the contact time with the reaction promoter, an increased contact surface with the reaction promoter in the reactor volume can contribute to a decrease in the reactor volume, which gives significant savings. Accordingly, the higher the ratio of surface to volume of the reactor, the smaller the volume of the reactor needed for this process.

Gaskets produced by industry vary greatly in shape and may include elements that increase surface area. For example, a cylindrical packing may have an axial channel, which increases both the inner and the outer surfaces and leads to an increase in the ratio of surface to volume. In addition, the cylindrical packing may include inner and / or outer ribs or other structure to provide an additional effective surface.

In an example more specific to biological reactors used in wastewater treatment, impurities serve as a power source, generally a source of carbon and / or nitrogen, for microorganisms living on the reactor packing. Bacterial metabolism turns impurities into metabolic products with a simple chemical structure, sometimes completely decomposing impurities to carbon dioxide and water in the aerobic method or to methane in the anaerobic method. But in any case, metabolic products usually do not have a negative impact on the environment.

Various methods of biological treatment are known. For example, US Pat. No. 4,634,672 describes biologically active compositions for treating wastewater and air, which are a polyurethane hydrogel containing activated carbon with a BET specific surface area of greater than 50 m ² / g, a polymer with cationic groups and capable of cell growth with enzymatic activity. US Pat. No. 4,681,852 describes a method for biological treatment of wastewater and / or air by contacting water or air with a biologically active composition of US Pat. No. 4,634,672. Experimental examples of these patents show that the method is not effective in reducing the concentration of contaminants in the effluent below 44 ppm. This is not acceptable because The Environmental Safety Agency (EPA) has stated in some examples that the concentration of certain contaminants (such as phenol) in the effluent should be below 20 parts per billion (ppb) (see Environmental Safety Agency 40 CFR, sections 414 and 416. Restrictive Emission Standards for Organic Substances, Plastics and Synthetic Fibers, Pretreatment Standards and New Sources Handling Standards (Federal Register, Vol.52, No. 214, Thursday, Nov. 5, 1989. Rules & Regulations, 42522).

US Pat. Nos. 3,904,518 and 4,069,148 describe the addition of activated carbon or fuller earth to a suspension of biologically active solids (activated pulp) in wastewater to remove phenol. Absorbers, apparently, act as a barrier to the effects of toxic bacteria impurities on their metabolic activity. On the basis of the approach proposed by the applicants, the so-called RAST-process was developed, which found application in industry despite long contact times, abundant pulp formation and problems of its decomposition, as well as the need for regeneration of waste coal.

Rehm and co-workers proposed using activated carbon in the aerobic oxidation of phenols using microorganisms on granular carbon, which serves as a porous biomass carrier. Using the ability of microorganisms to grow and remain fixed on the surface, Rehm used a carrier from granular activated carbon with a developed surface (1300 m ² / g), in the macropores of which cells are fixed as a porous biomass carrier in a circulation reactor to remove phenol [N.M. Ehrhardt and H.J. Rehm, Appl. Microbiol. BiotechnoL, 21, 32-6 (1985)]. The obtained "immobilized" cells were resistant to phenol to a concentration in the feed of approximately 15 g / L, while free cells remained stable to a concentration of not higher than 1.5 g / L. It has been suggested that activated carbon acts as a “buffer and storage”, protecting immobilized microorganisms by absorbing toxic high concentrations of phenol, leaving small amounts of phenol absorbed to participate in gradual biodegradation. This work has been improved by using a mixed culture immobilized on activated carbon [A. Morsen and H. J. Rehm, Appl. Microbiol. BiotechnoL, 26, 283-8 (1987)], where the authors noted that a significant number of microorganisms "sprouted" into the aquatic environment, i.e. a noticeable amount of pulp formed in the system.

Suidan and coworkers investigated in detail the similar anaerobic decomposition of phenol using a packed layer of microorganisms mounted on granular carbon [Y. T. Wang, M. T. Suidan and B. E. Rittman, Journal of Water Pollut. Control Fed., 58 227-33 (1986)]. For example, when using granular activated carbon fractions of 16 × 20 mesh as a carrier for microorganisms in the form of an expanded layer in the case of raw materials containing 358-1432 mg of phenol / l, a phenol concentration of about 0.06 mg / l (60 ppb) was achieved at hydraulic contact time (HRT) of about 24 hours. Somewhat later, a Berl saddle pad and a series of anaerobic reactors with an expanded granular activated carbon layer were used to demonstrate a high degree of conversion of oxidizable substances into methane Thu oxygen demand (COD), which almost completely proceeded in the reactor with an expanded layer [P.Fox, M.T.Suidan, and J.T.Pfeffer, ibid., 60, 86-92, 1988]. Resistance to decomposition of orthocresol and metacresol was also noted.

Givens and Sack, 42nd Purdue University of Industrial Waste Conference Proceedings, pp. 93-102 (1987) studied in detail the properties of coal-soaked polyurethane foam as a carrier for microbes in the aerobic removal of harmful impurities, including phenol. Porous polyurethane foam impregnated with activated carbon from the inside and containing microorganisms fixed on the outer surface was used in an activated pulp reactor similarly to the Captor and Linpor methods, which differ only in the absence of coal inside the foam. The method is accompanied by significant pulp formation and there is no positive effect of coal.

The Captor method itself uses a padding of porous polyurethane foam to create a large external surface on which microbes grow in an aeration tank for biological wastewater treatment. The above work describes the Captor method, modified by the presence of coal inside the foam. Evaluation of the Captor method itself in a pilot plant for two years showed a noticeable pulp formation with a significantly lower microbial density than stated [JA Heidman, R. C. Bremier and H. J. Shah, J. of Environmental Engineering, 114, 1077- 96 (1988)]. It should be noted that, as noted above, the Captor method is essentially an aerated pulp reactor, in which the pulp packing is held in the aeration tank using screens on the outgoing line. Excess pulp should be continuously removed by removing part of the packing using an unloading conveyor and passing the packing through pressure rollers to extrude solids.

H. Bettmann and H. J. Rehm, Appl. Microbial BiotechnoL, 22, 389-393 (1985) used a fluidized bed bioreactor for efficient continuous aerobic decomposition of phenol at a hydraulic contact time of about 15 hours using a Pseudomonas putida culture in a polyacrylamide hydrazide gel. The use of microorganisms in polyurethane foams for the aerobic oxidation of phenol in a shake flask has also been described [A. M. Anselmo et al., Biotechnology B.L. 7, 889-894 (1985)].

Known biodegradation methods have many disadvantages. For example, the main result of the widespread use of such methods is an increased amount of pulp, which poses a serious environmental problem due to the need to limit the emissions and spread of untreated pulp over land and sea [G. Michael Alsop and Richard A. Conroy, “Improved thermal processing of pulp with acids and bases ”, Journal WPCF, Vol. 54, No. 2 (1982), T. Calcutt and R. Frost, “Prospects for Pulp Processing,” Journal of the Institute of Water Pollution Control, Vol. 86, No. 2 (1987) and “The Crisis of Urban Waste Management and the Development of New Technologies”. Prepared by the United States Building Corporation, United States Building Corporation, P.O. Box 49704, Los Angles, Calif. 90049 (Nov. 22, 1988)]. The cost of pulp decomposition today can be several times higher than the cost of wastewater treatment.

To solve pulp problems, it was proposed to use anaerobic wastewater treatment systems [William J. Jewell “Anaerobic wastewater treatment”, Environ. Sci. Technol., Vol.21, No. 1 (1987)]. The biggest difference between aerobic and anaerobic systems is the number of newly formed cells. More than half of the substrate removed in aerobic systems can form a new microbial mass or pulp, while under anaerobic conditions its amount is usually less than 15% of the removed organic substances. However, anaerobic systems are limited by the number of substrates that can decompose or undergo changes, such as unsubstituted aromatic compounds [see N.S. Battersby & V. Wilson. "A review of organic substances on the potentials of anaerobic biodegradation of wastewater." Applied & Environmental Microbiology, 55 (2): p. 433-439, February 1989]. A significant drawback of most industrial processes is the formation of by-products - coke and coal tar - usually in the form of unsubstituted aromatic compounds [see J. M. Thomas, M. D. Lee, M. J. Scott and C. N. Ward, “Microbial ecology of the surface layer in places of uncontrolled release of creosote.” Journal of Industrial Microbiology, Vol.4, p.109-120, 1989].

Another disadvantage of some known biodegradation methods is that in these methods the concentration of organic harmful impurities does not decrease to reasonable values [preferably less than about 0.1 ppm (ppm)] at reasonable contact times (preferably less than about 24 hours). For example, in the method according to US patents Nos. 4681851 and 4634672 (see specific examples), the concentration of phenol impurities did not decrease below about 44 ppm.

US patent No. 2812031 relates to the extraction of phenols from aqueous solutions using polyurethane foam in the presence of hydrophilic fibers. The patent states that while polyurethane foams are relatively flexible, which can interfere with the phase contact necessary for adsorption, the problem is solved by using hydrophilic fibers that can closely contact the surface of the polyurethane and facilitate its wetting.

US patent No. 3617531 relates to a method for the selective adsorption of phenol from solutions in hydrocarbons. In this method, the solution is brought into contact with a polyurethane foam.

U.S. Pat. surface, inside or in the entire specified substrate.

US Pat. No. 4,165,281 discloses a method and apparatus for treating wastewater using microorganisms in which at least one non-woven fiber frame with a three-dimensional mesh structure in the aeration tank serves as a carrier for holding microorganisms on the surface and in the internodes of the frame and organic harmful impurities in sewage is oxidatively decomposed by microorganisms in the presence of oxygen.

US Pat. No. 4,820,415 discloses a method for biological treatment of wastewater by removing organic matter using microorganisms, in which a carrier for said microorganisms is added to said liquid, and said carrier comprises a filler-containing hydrophilic polymer with open pores in the form of separate particles, the improvement being the fact that these polymer particles, saturated with water and containing at least 70 vol.% biomass generated during the process, have an average density of slightly f density of said liquid and so suspended in the upper two-thirds of said liquid.

US Pat. No. 4,469,600 describes the biological treatment of wastewater in a reactor in the presence of a compressible open-cell carrier for biomass, the carrier being filled with bacteria and finely ground inorganic and / or organic compounds selected for water treatment before being used in the reactor, and then either stored or used in this method, the filled carrier being especially useful for reducing the time of the initial period of operation of an enterprise for wastewater treatment.

US patent No. 4576718 relates to the use of non-foaming, non-abrasive, highly concentrated polyurethane (urea) compositions with high ability to absorb water, which during their preparation do not contain cells capable of growth, as carriers for biomass in the biological treatment of wastewater. These carriers contain a filler in an amount of more than 15 wt.% And less than 95 wt.% (Calculated on dry matter). Fillers are selected from the group consisting of natural substances containing finely divided fossil fossil lignocellulose or its secondary products (e.g. peat, lignite, mineral coal or coke), activated carbon, finely divided residues from distillation, inorganic fillers, homogeneous or cellular particles of plastics (and more specifically polyurethane foam particles (scrap, waste)) and mixtures thereof. Polyurethane (urea) is hydrophilic and / or hydrophobic polyurethane (urea) and preferably contains cationic groups. These polyurethane (urea) carriers with a high filling have the ability to absorb water in an amount of more than 33 wt.% Water in a swollen carrier.

The prior art has described the exceptional properties of open-cell polyurethane foam as a carrier matrix for biologically active biomass, but has not addressed the problems associated with the use of this material in bioreactors. Mass transfer in bioreactors with a fixed film and polyurethane as a carrier matrix is limited by the structural integrity of the polyurethane foam and the compressive strength and, as a result, by the slip of water and air in a fixed-film reactor, as described by LJDeFilippi and F. Stephen Lupton, “Introduction to microbial decomposition of water effluents and its use in fixed-film reactors ", Chapter 2, p. 35-68, in the book" Biological treatment of harmful effluents ", ed. G.A. Lewandowski and L.J. DeFilippi, 1998. Repeated attempts have been made to overcome this drawback of polyurethane foam. One method used polyurethane foam attached to rotating plates of a rotating biological contactor (RBC), as described by Takahiro Suzuki, Satomi Yamaya and Masaru Ishida, “Hydrocarbon Treatment in a Spray Bioreactor with a Rotating Biological Contactor,” The Association for Environmental Health and Sciences, Soil Sediment and Water, August, 2001. However, these authors have shown that rotary biological contactors are not as efficient bioreactors as bubble spray reactors.

US Pat. No. 5,217,616 relates to the use of polyurethane foam randomly mixed with solid plastic gaskets that would prevent the polyurethane from compressing during aeration of the layer. Although the polyurethane layer does not compress, the mass transfer of oxygen from oxygen bubbles to the liquid phase is reduced compared to aeration of the liquid phase in the absence of packing.

Accordingly, it is desirable to develop a gasket for the reactor, which would create an increased surface to volume ratio while maintaining a low pressure drop, which would avoid excessive leakage of liquid through the reactor in order to achieve a narrow distribution interval of contact times in the reactor. In addition, it is desirable to use materials, such as polyurethane foams, with a potentially large ratio of surface to volume due to the presence of pores available for the reaction to proceed. Moreover, other important features and characteristics of the present invention will be apparent from the following detailed description and claims in combination with the accompanying drawings and the foregoing technical field and the background of the invention.

SUMMARY OF THE INVENTION

The invention provides a packed reactor suitable for a variety of applications in the chemical, pharmaceutical, and fermentation industries, for waste reduction, and in related industries. Packing options are characterized by alternating layers of packing. Stuffed reactors are characterized by a low pressure drop when passing through the beds, a reduced slip through the bed, and therefore an improved distribution of contact times in the reactor. The improved distribution of contact times has a significant effect on the quality of the outgoing process streams after processing, as well as the likely reduction in reactor size and cost savings.

The invention substantially eliminates one of the main disadvantages of packed reactors, especially bioreactors containing microorganisms, namely, the problem of uneven distribution of flow through the packing in randomly packed layers. The uneven distribution of flows arises because air and water try to find the channels of least resistance in the chaotic packing and biomass. As a result, dissolved nutrients, oxygen, and substrates are displaced mainly into zones adjacent to these formed channels, while other parts of the layer are not active in biological processes. In addition, since the growth of microorganisms is supported in areas adjacent to the channels, this further limits the distribution of biochemical reagents in a chaotically packed layer. The packing layers according to the invention, consisting of alternating layers of active substances (porous carriers for microorganisms), and hollow packing elements are a useful solution to the problem, as explained below.

In one embodiment, the invention provides a packed reactor consisting of a series of alternating layers. Alternating packing layers include a first packing layer of hollow elements and a second packing layer of porous support elements containing pores of about 15-20 pores per inch (ppi).

In another embodiment, the invention provides a packed reactor in the form of a series of alternating layers, where the first packing layer contains hollow packing elements randomly placed in a layer with a depth of up to 10 packing elements, and a second packing layer of porous hydrophobic foam carrier elements. The foam contains pores of about 15-20 ppi, and the porous support elements are randomly packed into a layer up to about 10 porous support elements in depth. The packing elements of the first layer and the porous support elements in the second layer are selected in shape so that the volume of voids in the reactor is about 50-65%.

In another embodiment, a packed reactor comprises a series of alternating packing layers, where the first packing layer consists of hollow elements randomly packed into a layer of about 10 packing elements in depth and the second packing layer includes porous hydrophobic foam carrier elements. Porous support elements are randomly poured into a layer up to about 10 porous elements deep. In addition, the packing elements in the first layer comprise mainly cylinders, and the porous support elements of the second layer have a substantially rectilinear shape.

Although the following detailed description mainly relates to the use of reactors in biological wastewater treatment methods, it will be apparent to those skilled in the art that the reactors of this invention are widely used in other fields of the chemical and biological industries, where the advantages of this invention will be fully apparent.

Brief Description of the Drawings

Figure 1 is a schematic cross-sectional view of a variant of a cylindrical packed reactor according to the invention.

FIG. 2 is a schematic cross-section for an embodiment of a rectilinear gasket reactor according to this invention.

Figure 3 schematically represents a foam element of the carrier in cross section.

4 is an example of a perspective view of a prior art packing element in the form of a hollow cylinder, such as a Jaeger HiFlow ™ packing element.

Figure 5 is a schematic cross section of the reactors used in example I.

6 is a schematic cross section of the reactors used in example II.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is essentially illustrative and is not intended to limit the invention or its scope. Moreover, the authors do not bind themselves to any specific theory presented in the sections given - the technical field, the background of the invention, a brief summary or the following detailed description.

The invention provides packed reactors in the form of a series of alternating packing layers that are widely used. For brevity and simplification of the description, it will mainly relate to wastewater treatment, given that the description of this option or area does not limit the application of the invention to this area only.

In one embodiment, this invention relates to a method for removing organic harmful impurities from wastewater. More specifically, this embodiment relates to a packed reactor and a method for removing such harmful impurities, especially harmful impurities and substances oxidized by the consumption of oxygen (COD), by aerobic biodegradation using porous biomass carriers. Of course, the removal of other contaminants, such as biologically oxidizable (BOD) substances, which are known to be removed by biodegradation, are also included in the scope of the present invention.

For wastewater treatment, a reactor is used having an inlet for a feed stream with one or more pollutants and an outlet for an exhaust stream in which the concentration of at least one of the pollutants is less than its concentration in the feed. The reactor is filled with biologically active biomass, which effectively lowers the level of one or more pollutants. Biomass is applied to many porous carriers, which together with biomass form many biologically active elements. Porous carriers are distributed in the reactor so that gaps remain between them. Thus, in general, biologically active elements include a substrate (namely, porous carriers) and an effective amount of one or more microorganisms capable of processing at least one of the contaminants in the feed stream under the conditions of the process in the reactor. Biologically active elements are characterized by a surface to volume ratio that is greater than that of hollow packing elements, which are distributed in the biomass to create contact between the flow of raw materials passing through the hollow packing elements, and all or part of the inner and outer surfaces of all biologically active elements adjacent to indicated intervals.

In addition, this invention relates to a method, apparatus and biomass, which provide improved parameters - speed, efficiency and adjustable biodegradation process. It is assumed that these improvements are due to improved contact and distribution of liquid, gas and / or solid phase in the technological scheme, equipment and biomass compared with technological schemes, equipment and biomass of the prior art with the same physical and operating parameters, i.e. configuration, components, hydraulic pressure, etc., but using only biologically active elements without hollow packing elements. The result of introducing appropriately distributed hollow packing elements is that the method, apparatus and biomass of the present invention contribute to biodegradation. In addition, the corresponding distribution of added hollow packing elements also increases the ability of the reactor to maintain a more stationary concentration of the pollutant in the effluent, despite the relatively greater fluctuation in the concentration of this pollutant in the feed stream compared to known methods, apparatus and biomass, which contains only biologically active elements, but without hollow packing elements. In the reactors according to the invention, the hollow packing elements are distributed in layers that alternate with layers of biologically active elements, creating gaps in the biomass in the reactor for liquid flow. This improvement in fluid flows through the reactor leads to many advantages over the prior art.

Biologically active elements include porous carriers, and these carriers are preferably made of an elastic polymer foam, which can be compressed (to some extent) at the working pressure used in the biodegradation method, which allows the liquid to penetrate through the pores in the foam. The apparatus and biomass of the present invention provide reduced compression of the active elements compared to prior art methods, apparatus and biomass with the same structural and operating parameters and active elements, but without hollow packing elements. Layer-by-layer arrangement of biologically active elements and hollow packing elements provides fast mass transfer of oxygen during biodegradation. The apparatus and biomass of the present invention also lead to increased mass transfer compared to methods, apparatus and biomass of the prior art with the same structural and operating parameters and active elements, but without hollow packing elements along with active elements.

The present invention in a variant of biodegradation will be more clear when considering the included figures. Of course, specialists in this field will be obvious and other variants of the invention relating to other chemical and biological processes.

1 and 2, the reactor 100 is intended for use in an embodiment of the present invention for biodegradation of substances contained in raw materials using aerobic or anaerobic microbes. As used herein, the term “biodegradation” includes the metabolic decomposition of organic compounds into lower molecular weight compounds, the metabolic conversion of inorganic nitrogen compounds such as ammonia (NH ₃ ) and nitrogen oxides (eg NO ₃ , NO _2, and the like) to nitrogen gas and dehalogenation by removal of halogen atoms such as chlorine, fluorine, bromine and / or iodine from halogenated organic compounds.

The reactors 100 in FIGS. 1 and 2 are horizontal and vertical in accordance with their construction and configuration. However, in the practice of the present invention, the construction, configuration and structural materials can vary widely and other structures and configurations can be used in the practice of the present invention, provided that the entire layer 102 or part of it in the reactor is stationary or substantially stationary. As used herein, the term “fixed bed or substantially fixed bed reactor” refers to a reactor in which a plurality of biologically active particles are stationary or substantially stationary when the flow of feed through the reactor is moving. In addition, the term “packing layer” means a layer in a reactor, including packing of any kind, regardless of whether (or will contain) the packing of biomass.

The reactor 100 comprises a bed 102, which includes biologically active elements 110, biomass 116 and hollow packing elements 120. In biomass 116, voids or empty or practically empty areas 115 remain between the active elements 110 and packing elements 120. The process stream may flow through these empty areas 115. The active elements 110 are kept from being entrained by forces directed along the process stream by a porous screen or plate 136. The screen 136 is sufficiently porous to allow an effective amount of gas or liquid to flow through it. STI required for the metabolism of microorganisms on the active elements during biodegradation. The reactor 100 also includes diffusers 138 for supplying gas to the reactor 100 and a feed flow distributor 130.

As shown in the embodiments of FIGS. 1 and 2, the packing layers 102 in the reactors 100 include hollow packing elements 120 that are adjacent to the layers of active elements 110. In principle, any of a variety of structures capable of forming empty or nearly empty areas for fluid to pass through. Accordingly, the hollow elements of the packing 120 may have a different shape. However, these forms can optionally be selected in such a way as to facilitate the formation of gaps 115 between the active elements and the hollow elements of the packing 120 in the biomass 116 for the passage of liquid flow through the gaps 115.

In one embodiment, the carriers 114 for the biologically active elements 110 (see FIGS. 1, 2, and 3) are rectangular porous elements such as cubes, and the hollow elements of the packing 120 can then be substantially cylindrical. As shown in FIG. 4, Jaeger HiFlow ™ packing members are an example of hollow packing members 120. In this case, the packing members 120 are in the form of thin cylindrical cups 122 that contain four through holes 126, one on each quarter of the outer surface. In addition, the cup 122 contains a pair of intersecting vertical inner walls (or ribs) 124, which increases the inner surface and the ratio of surface to volume in the packing member 120. The packing members have a rigid hollow frame 128 that defines the shape of the structures.

Although the shape of the hollow elements of the packing 120 is not critical and you can use almost any shape that creates gaps for flow, the options shown in figure 4 are almost cylindrical.

During operation of the reactor, a feed stream flowing through empty regions 115 and hollow packing elements 120 provides contact between the liquid and all or substantially all of the inner or outer surface of all or almost all of the adjacent biologically active elements 110.

To achieve maximum contact between the process stream and the biomass on the active elements 110, the hollow elements of the packing 120 must contain passages (voids or gaps) through which the process stream can flow. Typically, the passages or voids in the hollow elements of the packing 120 comprise at least about 40 vol.%, Preferably at least about 50 vol.%, More preferably at least about 80 vol.% And most preferably at least about 95 vol.% of the total volume of the packing elements 120. Accordingly, the ratio of surface to volume for structures 120 is less than for biologically active elements 110.

As shown in FIG. 3, the biologically active elements 110 are composed of a substrate 114 and one or more types of microorganisms 112, usually aerobic or anaerobic, that are capable of converting at least one of the substances contained in the effluents, on the surface, inside or on the surfaces and inside the substrate 114. The relative location and ratio of the biologically active elements 110, the empty or almost empty areas 115 in the biomass 116 and the hollow packing elements 120 are critical for realizing the advantages of the present invention. The ratios of the components in the packing layer and their location should be optimized to create a contact between the process flow of raw materials and all or part of the external or internal surface of the biologically active elements 110.

Although the authors did not want to be bound by any theory, it was suggested that the location and ratio of the components of the packing layer lead to increased mass transfer in the gas / liquid / solid system and their distribution and therefore improve the contact between the decomposed substance in the process stream and microbes 112 by surface, inside or on the surface and inside of the substrate 114 in the elements 110. This increases the efficiency of the biodegradation method. An advantage of improved liquid distribution is that the biodegradation method, apparatus, and biomass of the present invention are more efficient than the prior art method, apparatus, and biomass in which there are no hollow packing elements in the reactor, such as those described in US Patent Nos. 4,567,718 and 4983299 and PCT WO 90/11970. Moreover, the data show that another advantage over prior art methods, reactors and biomass is that the improved distribution provides better resistance to reactor malfunctions, as explained below.

In General, the present invention offers a significant increase in reactor productivity compared to other reactors without hollow packing elements 120. For example, the relative ratios and localization of the elements 110 and hollow packing elements 120 in the biomass 116 of the reactor 100 according to this invention are such that the volumetric removal rate is at least one (polluting) substance from the feed stream at a contact time of about 10 hours is greater than the speed in another reactor with packing without hollow elements 12 0, but of a different configuration, and the components operate in the same manner as in the reactor 100 of the present invention, even if the number of active elements 110 in this other reactor is equal to the sum of the number of packing elements 120 and the number of active elements 110 in the reactor of the present invention. Preferably, the relative localization and ratios of the elements 110 and the hollow elements of the packing 120 are such that the volumetric rate of removal of (contaminants) by the reactor of the present invention is greater than about 10%, preferably more than about 20%, more preferably equal to or more than about 30% and most preferably more than about 50-100% than the removal rate in another reactor in which the packing layer consists of only active elements 18 and does not contain hollow packing elements 120. The elements 110 and the hollow elements of the packing 120 are preferably brought together so that at least about 50% of the inner and outer surfaces of at least about 50% of the total number of biologically active elements 110 are adjacent to the layer including the hollow elements of the packing 120, so that the active elements 110 are in contact with the feed stream flowing through the packing elements 120. In more preferred embodiments, the active elements 110 and the hollow packing elements 120 are arranged laid in such a way that at least about 60% of the inner and outer surfaces of at least about 60% of the total number of active elements 110 are adjacent to a layer that includes hollow packing elements 120, as a result of which the active elements 110 are in contact with the feed stream, flowing through the packing elements 120. In the most preferred embodiments of the invention, the active elements 110 and the hollow packing elements 120 are brought together so that at least about 80% of the total number of biologists especially active elements 110 were located next to the layer, which includes hollow elements of the packing 120, and as a result, the active elements 110 are in contact with the process flow of raw materials flowing through the elements of the packing 120.

Biomass 116 contains an effective amount of hollow packing elements 120 dispersed therein. As used herein, the term “effective amount of hollow packing elements 120” means a quantity capable of increasing a gas / liquid / solid distribution in biomass 116 and a volumetric removal rate at a contact time of about 10 hours compared with similar biomass only or almost exclusively in the active elements 110. In principle, the number of hollow elements of the packing 120 can be determined in terms of a percentage of the volume of bi mass in the volume of 115. In preferred embodiments of the invention, the total volume fraction of the packing layer 102, consisting of hollow packing elements 120, is about 30-90 vol.%, and the rest of the volume is made up of only or practically only biologically active elements 110. In particularly preferred In embodiments of the invention, the total% of the volume of the packing layer 102 in the reactor occupied by the hollow packing elements 120 is 80-40 vol.%, and the rest of the volume falls only or almost exclusively on the active elements 110. In the most preferred s embodiments, the total% volume of the packing layer 102 in the reactor occupied by hollow padding elements 120, 50-70 vol.%, and the remaining fraction of the volume falls mainly on the active elements 110.

The structure and composition of the structural hollow elements of packing 120 may vary over a wide range, provided that the desired results are obtained by enhancing biodegradation and achieving greater resistance to concentration fluctuations in the waters entering the treatment. The only requirement is that the material of the elements 120 is not reactive and suitable for use in a reactor, in particular in microbial processes. For example, the hollow elements of the packing 120 may be made from organic or inorganic substances. Examples of inorganic materials suitable for the manufacture of hollow packing elements are ceramics such as bentonite, kaolinite, kieselguhr, diatomaceous earth, aluminum, silicon oxide, zirconium oxide, barium titanate, synthetic carbides, synthetic nitrides and synthetic borides, glasses such as sodium calcium-silicate glasses, lead glasses, borosilicate glasses, laser glasses, silica-based glasses and glass-ceramics, etc. Suitable organic materials for the manufacture of packing elements include polymers such as polyamides, polyesters, polyester carbonates, polycarbonates, polyolefins and the like. Preferably, the structures 22 are molded from rigid plastic such as polypropylene or polyethylene.

The shape of the packing elements can vary widely; the only requirement is that their shape has a sufficient amount of open space inside or around them, so that during operation in the packing there are passages to allow fluid to flow through the reactor. The packing elements 120 used in the practice of this invention are in the form of particles. As used herein, the term “in the form of particles” simply means that the size of the packing elements is smaller than the size of the selected reactor, which may contain a plurality of packing elements. The size and shape of the hollow packing elements may vary in length, thickness, width, diameter or other dimensional parameters. For example, the packing may be in the form of particles of a regular shape, such as cubes, rods, rectangles, cylinders and hexagonal particles and the like, or they may have an irregular shape. The particle size (length, thickness, width and diameter or equivalent diameter for an irregularly shaped structure) can vary over a wide range and is not critical, but depends on the size of the reactor. The particle size is preferably about 0.10-12 inches for a reactor with a diameter of 20 feet, and for larger or smaller reactors, appropriate scaling can be used. More preferred particle sizes are about 0.5-5 inches and most preferred particle sizes are about 0.75-3 inches, with a particle size of about 1.0-2.0 inches being chosen for a 20 foot diameter reactor.

The biologically active elements 110 used in the practice of this invention also have the form of particles. As used herein, the term "in the form of particles" simply means that the size of the elements 110 is smaller than the size of the reactor 100 and as a result, the reactor 100 can contain many elements 110. The size and shape of the elements 110 can vary greatly in length, thickness, width and diameter. For example, the elements 110 may be in the form of particles of a regular shape, such as cubic, in the form of rods, rectangular, cylindrical, hexagonal, etc., or may have an irregular shape. Particle size (length, thickness, width and diameter for regular shape 110 and equivalent diameter for irregularly shaped elements) can vary over a wide range and is not critical, but depends on the size of the reactor. The particle size is preferably about 0.10-12 inches for a reactor with a diameter of 20 feet. More preferred particle sizes are about 0.5-5 inches and most preferred particle sizes are about 0.75-3 inches, with a particle size of about 1.0-2.0 inches being chosen for a 20 foot diameter reactor.

One of the critical requirements for elements 110 is that the ratio of surface to volume (taking into account both internal and external surfaces) be greater than that of hollow packing elements 120. The greater the difference in this ratio, the more effective the method. Accordingly, it is recommended to choose hollow packing elements 120 and active elements 110 so that the difference in the ratio of surface to volume is as large as possible while maintaining the necessary relative position and ratio of the elements 110 and hollow packing elements 120 in biomass 116. It is preferable that the ratio of the inner and outer surfaces of the elements 110 was at least about 20 times greater than that of the hollow elements of the packing 120, more preferably at least imerno 10 times and most preferably at least about 5 times greater than that of hollow stuffing elements 120.

Biologically active elements 110 include a substrate 114, as shown in FIG. 3, and the substrate 114 is preferably porous. This allows the process stream to flow inside the elements 110 and move through them. In preferred embodiments of the invention, substrate 114 comprises about 2-60 pores per linear inch ("ppi"). More preferably, the number of pores per linear inch is about 5-30, and most preferably about 10-20. In selected embodiments, the number of pores per linear inch is about 10-15.

Preferably, the substrate 114 is resistant to the forces arising in the reactor, for example, shear or abrasion, and preferably has a high crushing strength. In preferred embodiments of the invention, to achieve optimal economic effect, substrate 114 is semi-elastic with a density of about 2 pounds per cubic foot. However, substrates with higher densities of about 4-5 pounds per cubic foot and even more can be used. It should be understood that the density of the substrate determines the economy of the invention, but not its operating mode; the invention can be put into practice with a wide range of substrate densities, even if different intervals have different economic indicators.

The amount of substrate 114 in biologically active elements 110 can vary widely. Typically, the amount of substrate 114 is about 50-95 wt.% Based on the total weight of biologically active elements 110. In preferred embodiments, the amount of substrate 114 is about 70-85 wt.%, Calculated as described above.

The substrate 114 is made from any substances capable of forming biologically active elements 110. Suitable substances include inorganic substances and organic plastics. Examples of suitable substances for the manufacture of substrates 114 are synthetic and natural polymers such as polyamides, for example, poly (hexamethylene adipamide) (nylon 66), poly (4-aminobutyric acid) (nylon 4), poly (6-aminomexanoic acid) (nylon 6 ), poly (hexamethylene sebacamide) (nylon 6.10) and the like; polyesters such as poly (ethylene terephthalate), poly (butylene terephthalate), poly (1,4-cyclohexane dimethylene terephthalate) and the like; polyolefins, such as polyethylene, polypropylene, poly (4-methylene), polystyrene and the like; polyvinyl derivatives such as polyvinyl alcohol, poly (vinyl methyl ether), poly (vinyl methyl ketone), poly (vinyl pyrrolidone) and the like; polyacrylates such as polyacrylic acid, polymethacrylic acid, poly (methyl acrylate), poly (methyl methacrylate), polyacrylonitrile, polyacrylamide, poly (methacrylamide) and the like. Other polymeric materials suitable for the preparation of a polymeric substrate include polyurethanes, such as polymers prepared by the reaction of diisocyanates such as toluene diisocyanates, diphenylmethanediisocyanates, hexamethylene-1,6-diisocyanate, dicyclohexylmethanediisocyanate, 1,5-naphthalenediisocyanate, phenediophenediophenedi 2,4-toluene diisocyanate, 4,4'-diphenylmethanediisocyanate, 3,3'-dimethyl-4,4'-diphenylmethanediisocyanate, 3,3'-dimethyl-4, 4'-diphenyl diisocyanate, 4,4'-diphenylisopropylidene diisocyanate, 3, 3'-dimethyl-4,4'-diphenyldiisocia ata, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenyl diisocyanate, dianizidindiizotsianata, toluidindiizotsianata, hexamethylene diisocyanate, 4,4'-diisocyanatodiphenylmethane and the like with diols such as glycerol, trimethylol propane, 1,2,6-hexanetriol, methyl glycoside pentaerythritol, sorbitol, ethylene glycol, diethylene glycol, as well as with polyesters containing terminal hydroxyl groups obtained by direct esterification of dicarboxylic acid with an excess of bifunctional alcohol (such as poly , poly (ethylene adipate), poly (1,4-butylene adipate), poly (1,5-pentylene adipate), poly (1,3-butylene adipate), poly (ethylene succinate), poly (2,3-butylene succinate), with polyether diols, such as those obtained by the reaction of the starting compound, containing active hydrogen atoms, such as alcohol, polyalcohols, diphenols, aliphatic diamines or polyamines or aromatic diamines or polyamines, as well as ethylenediamine, diethylene triamine and 4,4-phenylmethanediamine, with alkylene oxides such as styrene oxide, butylene oxide, propylene oxide or epichloromethane alkylene oxides.

In preferred embodiments of the invention, the substrate 114 is made of flexible, semi-elastic or rigid polymer foam. A more preferred polymer material for the substrate in this invention is an open-cell elastic foam with relatively high permeability to a process fluid stream of at least about 60%, preferably at least about 75%, more preferably at least about 85%, and most preferably at least about 95%. The foam used in the practice of the present invention in a fixed bed configuration should be able to absorb the process stream. Finally, it is important that the foam has an intersecting pore structure so that voids in the foam are desirably at least about 40 vol% and can reach up to about 98 vol%.

Preferably, the voids in the foam of substrate 114 comprise about 40-98 vol.% Of its volume, more preferably about 60-96 vol.% And most preferably about 85-95 vol.%. "Elastic cellular polymeric materials" are usually easily compressed. As used herein, the term “elastic cellular polymeric materials” refers to a cellular organic polymeric material that will not break if a single-layer specimen of 200 × 25 × 25 mm is bent five times around a mandrel with a diameter of 25 mm at a constant speed at a temperature of 18-29 ° C, in accordance with ASTM D 1565, D 1667, D 3574 and D 3575. Due to their elasticity, the substrates themselves tend to agglomerate and lose their original shape under pressure, which can be created by buoyancy when these the elements are impregnated with a liquid with a higher density than their own, which leads to a decrease in the effective ratio of the surface to volume and prevents the flow of the process flow through these elements and around them, thereby reducing the mass transfer rate during reactor operation. When layers of hollow elements 120 are added, agglomeration of elastic elements 110 is noticeably reduced.

Theoretically, it can be assumed that an increased fluid flow through and around elements 110 and lower buoyant forces acting on the elements will lead to more efficient biodegradation and / or increased reactor failure resistance due to fluctuations in the concentration of impurities in the feed stream compared to the method or a reactor in which only elements 110 are used without hollow packing elements 120.

In more preferred embodiments of the invention, substrate 114 is made from open-cell polyurethanes, such as cross-linked polymers, which can be foamed using a suitable foam reagent such as nitrogen, helium, carbon dioxide, azoic acid diamide and the like, the formation of foam with open cells, the structure of the voids in which is described above. In these preferred embodiments of the invention, the substrate 114 can be made and foamed in the presence of selected microorganisms in the absence of negative effects on them.

In particularly preferred embodiments of the invention, substrate 114 is prepared from cross-linked hydrogels of polyurethanes. Such substances are available commercially or obtained by known methods. For example, such materials can be prepared by reacting pre-prepared polyisocyanates with water (which optionally contains diamines or polyamines as chain length reagents or crosslinking reagents) or by reacting a suitable polyol with a corresponding diisocyanate or polycyanate. Suitable polyols include long chain aliphatic diols and polyoxyalkylene esters. Pre-obtained polyisocyanates contain terminal isocyanate groups and are prepared by reacting polyoxyalkylene esters with an excess of diisocyanate or polyisocyanates. Examples of suitable polyoxyalkylene esters include compounds with a molecular weight of about 500-10000, preferably about 2000-8000, and they contain at least two active hydrogen atoms and at least 30 wt.% Hydroxyethylene groups based on the total weight of the polyester. Other suitable oxyalkylene groups include hydroxypropylene, hydroxybutylene and the like. This type of polyesters is prepared by reacting compounds containing reactive hydrogen atoms, such as alcohol, polyalcohols, diphenols, polyphenols, aliphatic diamines, aliphatic polyamines, aromatic diamines or aromatic polyamines, with suitable alkylene oxide, such as ethylene oxide, propylene oxide, butylene oxide, etc. Suitable diisocyanates include toluene-4,4'-diisocyanate, toluene-2,4-diisocyanate, toluene-2,2-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, diphenylmethane-2, 2'-diisocyanate, toluene-2,6-diisocyanate, hexamethylene-1,6-diisocyanate, and the corresponding diamines and polyamines include aliphatic, cycloaliphatic and aromatic di- and polyamines, such as ethylenediamine, hexamethylenediamine, diethylenetriamine, hydrazine, guanidine, guanidine , N, N'-diisopropylhexamethylenediamine, 1,3-bisaminomethylbenzene, N, N'-bis- (2-aminopropyl) ethylenediamine, N, N ' - (2-aminoethyl) ethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-dimethylamino-3,3'-dimethyldiphenylmethane, 2,4'-diaminodiphenylmethane, 2,4-diaminotoluene, 2,6-diaminotoluene, etc. P.

Biological active elements 110 may include various optional ingredients, such as substances with cationic groups. Examples of such substances are conventional ion-exchange resins with cationic groups or other polymers whose structures contain positively charged nitrogen atoms, for example, esters of polyaminocarboxylic acids with cationic groups, polyacrylamides with cationic groups, polyethyleneimines with cationic groups, copolymers of acrylonitrile, styrene and dimethylaminoaminoethyl methacrylate , and condensation products of diethylene triamine and maleic anhydride with cationic groups containing cationic groups isobutylene copolymers and maleic anhydride, followed by imidation with suitable diamines. The content of polymers with cationic groups in the composition according to the invention can vary widely and is usually about 0.2-20 wt.% Based on the total weight of biologically active particles, preferably about 0.5-15 wt.% And most preferably about 1-10 wt. % based on the total weight of the reaction mixture for the manufacture of the composition. Examples of other optional components that can be used in the practice of this invention are density enhancing agents such as barite, metal powder, rubber powder, clay powder, pumice powder, glass powder, powder obtained from seeds and shells of olives and nuts, and mountain flour; density reducing agents, such as small polystyrene globules, wood powder, plastic waste powder, hollow microspheres, and polyethylene foam flakes; colorants such as coloring pigments and paints; short fibers of an organic or inorganic base, such as glass fibers and gelling macromolecular substances, such as varieties of cellulose, alginate, starch and carrageenan.

For example, in one preferred embodiment of the invention, substrate 28 is prepared from "hydrophobic polyurethanes" which are absorbers for organic substances such as phenol. As used herein, the term “hydrophobic polyurethanes” means a family of polymers with repeating urethane groups of the formula: —N (H) C (O) O— or —N (H) C (NH) O—, preferably of the formula: —N (H) C ( O) O-.

Hydrophobic polyurethanes are not wetted by water. That is, a drop of water on the surface of the polyurethane has a contact angle of more than 0.0 degrees and preferably more than 90 degrees according to the goniometer. In preferred embodiments of the invention, hydrophobic urethanes are characterized by a molar ratio of carbon and hydrogen atoms to oxygen and nitrogen atoms in the polymer backbone of greater than 1.4. The upper level of hydrophobicity of the polyurethane is not critical, and generally hydrophobic polyurethanes with higher hydrophobicity are preferred. In such preferred embodiments, the hydrophobic polyurethanes are selected so that the molar ratio of carbon and hydrogen atoms to oxygen and nitrogen atoms is equal to or greater than about 2.5. Among the more preferred embodiments of the invention, those in which the molar ratio of carbon and hydrogen to oxygen and nitrogen atoms is equal to or greater than about 3.0 are most preferred.

Examples of suitable hydrophobic polyurethanes are the polyurethanes described above, in which molar amounts of the polyisocyanate and polyol reagents are selected so as to achieve the desired hydrophobicity. The adsorption and / or absorption of substances in a feed stream, such as substituted and unsubstituted phenols, on the surface and inside of the polyurethane foam depends on both the type of polyol used and the proportion of cross-linked isocyanates in the foam. In preferred embodiments of the invention, aromatic isocyanates and / or polyols are characterized by an increased ratio of carbon and hydrogen to oxygen, such as polyols containing an increased number of carbon atoms, such as in propylene glycol polyester and in other polyols with suspended aliphatic groups. In the most preferred embodiments, in a hydrophobic polyurethane foam it is better to increase the number of aromatic groups, specifically aromatic isocyanates, to improve the hydrophobic characteristics of the polymer. Preferably, the hydrophobic fragments of one or more types of polyurethane contain more than about 15 wt.% Of aromatic isocyanate and less than about 85 wt.% Of fragments of one or more types of alkylene glycol polyester, with at least about 40 wt.% Of the fragments from diol introduced from such glycols in which repeating alkylene groups include more than three carbon atoms, especially poly (propylene oxide). Among these preferred embodiments of the invention, more preferred are those in which the hydrophobic polymer contains at least 50 wt.% Alkylene glycol polyester and more than about 20 wt.% Aromatic isocyanate. In particularly preferred embodiments, the polyol content in the hydrophobic polyurethane is at least 80 wt.%, Of which less than about 60 wt.% Is polyethylene glycol and less than about 25 wt.% Aromatic isocyanate. In even more preferred embodiments, the polymer contains more than about 70 wt. % polyethylene oxide and less than about 30 wt.% aromatic isocyanate.

Used in the practice of this invention, anaerobic or aerobic microorganisms 112, which are selected for the decomposition of target substances in the feed stream by this method, are well known to specialists in this field. Microorganisms can be used as a pure strain or in a mixture of microorganisms. Although anaerobic microorganisms often decompose harmful impurities more slowly than aerobic ones, the anaerobic method can be used to decompose harmful impurities or an intermediate product of the aerobic method to a level of non-toxicity or to a harmless substance. You can use a wide range of different microorganisms 112, and these can be natural microorganisms 112 or genetically modified microorganisms 112. The only requirement is that microorganisms 112 must be capable of decomposing harmful impurities to the desired output level over a desired period of time. In preferred embodiments of the invention, microorganisms 112 are obtained from wastewater containing harmful impurities, or from soil that has been in contact with wastewater.

In the method, liquid flows, for example, a liquid feed stream containing one or more biodegradable substances, are introduced into the reactor 100 through a distributor at the inlet 130, passed through the reactor 100, and removed from the reactor through the outlet 134 at a rate sufficient to reduce the concentration of at least one of the harmful substances in the exhaust stream to the desired values. The method of this invention can be carried out under aerobic or anaerobic conditions. In preferred embodiments of the invention using aerobic microbes, the method is carried out under aerobic conditions in the presence of a gas containing an effective amount of oxygen. In a preferred embodiment, it is important that the reactor 100 contains the necessary amount of oxygen for the desired microbial metabolism and decomposition of harmful impurities. The amount of oxygen needed in different situations varies over a wide range and will depend largely on the needs of the specific microorganisms used in the method, as well as other factors known to those skilled in the art. In general, the amount of oxygen distributed in the feed stream is approximately 2 mg of oxygen per liter of aqueous feed. In preferred embodiments of the invention, the amount of oxygen is about 5-10 mg / L of raw material and in most preferred embodiments of the invention, the amount of oxygen is about 6-8 mg / L of raw material. In preferred embodiments of the invention, the gas is uniformly or substantially uniformly distributed throughout or part of the biologically active biomass. The method of supplying gas to the reactor 100 may be different. Gas may be supplied to the reactor 100 by conventional methods. For example, in a vertical reactor or in an upflow reactor 100 in FIG. 2, gas is supplied to the reactor 100 from the bottom of the reactor 100 through small diffuser 138 through a diffuser 138 and removed from the bioreactor through exit 132. The gas can be introduced at different points along the length if desired reactor 100 vertically (not shown). In the embodiment of FIG. 1, in which the reactor 100 is horizontal, gas can be supplied along the length of the horizontal reactor at different points to achieve a substantially uniform distribution of gas in the feed stream in the reactor 100. In this embodiment, the upward gas flow is perpendicular or substantially perpendicular to the direction the liquid feed stream from the diffuser 130 to the side outlet 134. In the most preferred embodiments of the invention, the reactor 100 is horizontal, with the gas uniformly or substantially uniformly aspredelyaetsya throughout or substantially throughout the reactor 100. In these most preferred embodiments, the gas is supplied to the reactor 100 along the horizontal length of reactor 100, as shown in Figure 1. With this method, a more uniform distribution of gas in the feed stream is achieved.

The temperature of the implementation of the method can vary in a wide range and will depend on the choice of specific microorganisms. In General, the method is carried out at a temperature high enough to ensure the metabolism of microorganisms, and low enough not to kill microorganisms. The method is usually carried out at temperatures of about 5-65 ° C. It is preferable to carry out the method in the range of about 15-65 ° C, more preferably about 20-40 ° C, and most preferably about 25-35 ° C.

In this method, the liquid stream is treated for a time sufficient to reduce the concentration of at least one of the substances in the effluent to the desired value. In General, for flows of liquid raw materials in which the concentration of at least one substance is equal to or less than about 12000 ppm (preferably equal to or less than about 6000 ppm, more preferably equal to or less than about 3000 ppm, more preferably equal to or less than about 2000 ppm), contact time equal to or less than about 200 hours, preferably equal to or less than about 100 hours, more preferably equal to or less than about 20 hours, and most preferably equal to or less than 10 hours, is sufficient to reduce the concentration of at least one harmful substance in the effluent to about 100 ppm (ppm), preferably equal to sludge less than about 10 ppm, more preferably equal to or less than about 1 ppm most preferably equal to or less than about 0.1 ppm According to federal or state regulation, the concentration of these substances at the outlet must be chosen equal to or less than about 0.02 ppm. The specific contact time in the process depends on many factors, including, but not limited to, the amount and type of organic substances in the feed, the operating temperature, the presence of other substances in the feed, and the density of microorganisms in the reactor.

Variants of this method have increased resistance to "failure". "Failure" usually means a jump in the concentration of harmful impurities removed in the reactor. Typically, such altered concentrations move along the reactor and are measured as the corresponding jump in the concentration of harmful impurities in the effluent from the reactor. When such jumps or changes occur and the corresponding variations in the concentration of the substance in the exhaust stream are minimal or leveled, they say that the reactor is resistant to failure. In embodiments of the invention, the reactors are fault tolerant. Thus, when the concentration of a pollutant or a harmful impurity in an inlet stream changes by a certain amount, the concentration of a harmful impurity in an exhaust stream usually increases by a value less than or equal to about 25% of the value of the initial change in a time corresponding to the time of one hydraulic contact (HRT). More preferably, the change in the effluent is less than or equal to about 10% of the increase in concentration in the inlet during one HRT or less. Most preferably, the concentration at the outlet increases by less than or equal to about 1% of the increase in concentration at the entrance, for about one HRT or less.

The streams that can be processed by the method of the present invention can be very different. For example, such streams may be gas streams containing one or more substances, or they may be liquid streams. In preferred embodiments of the invention, the liquid or aqueous streams contain one or more dissolved or suspended substances. The harmful impurities contained in such streams can be different. The only requirement is that at least one of the substances can decompose or participate in the metabolism of aerobic or anaerobic microorganisms. For example, these substances may be inorganic nitrogen-containing compounds, such as ammonia and nitrates. These substances may also be organic. Examples of such harmful organic impurities are phenols, such as phenol, cresols, resorcinol, catechin, halogenated phenols, such as 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, pentachlorophenol, nitrophenols such as 2-nitrophenol and 4-nitrophenol and 2,4-dimethylphenol. Another important class of organic important impurities includes aromatic hydrocarbons such as benzene, toluene, xylenes, ethylbenzene, etc. Polynuclear aromatic hydrocarbons constitute an important subclass and are represented by naphthalene, anthracene, chrysene, acenaphthylene, acenaphthene, phenanthrene, fluorene, fluoranthene, naphthacene and pyrene. Other such substances are halogenated alkanes such as trichloroethane and the like.

In preferred embodiments of the invention, substances that are often found in wastewater are treated to treat industrial effluents. For example, various substituted and unsubstituted phenols, such as phenol, chlorophenols and nitrophenols, and aromatic compounds, such as benzene, are those harmful impurities that can be processed in the method of this invention, and substituted and unsubstituted phenols, especially phenol, are the most common harmful impurities. Phenol is found in wastewater from phenol producers, phenol consumers for the production of phenolic resins, from coal tar processing equipment, from pulp mills and other delignification plants. This is not to say that the method can or should be used only to process such flows. The method of this invention can be used for any raw material containing one or more substances, the concentration of which must be reduced.

Initial concentrations of the substances contained in the effluents used in this invention can vary over a wide range. One of the advantages of this invention in comparison with the biodegradation methods of the prior art is that it can be used to process liquid streams containing relatively high amounts of substances, which should be removed or their concentration reduced. The concentration of substances in the process streams, which should be removed or lower their concentration using the method of the present invention, are "biologically processed concentrations". As used herein, the term “biologically treatable concentrations” refers to substances that must be removed or reduced to levels such that the decomposition of harmful impurities under the influence of microorganisms is not inhibited. The effluents of industrial plants, such as the production of phenol, the processing of coal tar, may contain substances that should be removed or their concentration reduced from an excessively high value of 20,000 ppm, which may create an obstacle to the application of this method. It is preferable to reduce their concentration to a biologically treatable concentration using conventional techniques such as solvent extraction, steam distillation, and the like. Typically, the concentration of substances to be removed or reduced in liquid streams (preferably water streams) is equal to or less than about 12,000 ppm. Obviously, a lower concentration is not critical and does not limit the process. In preferred embodiments of the invention, the concentration of substances to be removed or reduced is equal to or less than about 6000 ppm. and in particularly preferred embodiments of the invention, the concentration of substances to be removed or reduced is equal to or less than about 3000 ppm. Among these particularly preferred embodiments of the invention, those in which the concentration of substances to be removed or reduced are equal to or less than about 2000 ppm are most preferred. and a concentration of about 1000 ppm is a particularly good option.

The pH of raw materials containing harmful impurities should be set so that it is optimal for biodegradation. Typically, the pH is selected in the range at which metabolism of the target harmful impurities is possible. In preferred embodiments of the invention, the pH of the feed is 6-9 and in the most preferred embodiment of the invention, the pH of the feed is 6.5-7.5.

Nutrients may also be needed. Such substances can be added in the form of additives such as fishmeal, soybean oil, peanut oil, cottonseed oil, and usually salts — phosphates, sodium, potassium, ammonium, calcium, sulfates, chlorides, bromides, nitrates, carbonates, or the like. Usually, sufficient amounts of additives are already present in the aqueous feed to meet the minimum requirements of microorganisms.

The feed water stream is introduced into the reactor 10 by conventional methods and passed through the reactor for an “effective hydraulic retention time”. As used herein, the term “effective hydraulic retention time” means enough time to reduce the concentration of harmful impurities in the effluent to a desired level. The hydraulic retention time can vary over a wide range and usually depends on factors such as the concentration of harmful impurities in the initial water stream, the maximum permissible concentration of harmful impurities in the waste water, microorganisms contained in biomass, the nature of the harmful impurity, etc. An advantage of the method of this invention is that a reduction in the concentration of harmful impurities can be achieved in a relatively short hydraulic holding time. In preferred embodiments of the invention, the hydraulic retention times are equal to or less than about 72 hours, and in particularly preferred embodiments of the invention, these times are about 1-48 hours. Among these particularly preferred embodiments of the invention, those in which the hydraulic retention time is about 2- 24 h

In the exhaust stream, the concentration of harmful substances is reduced and there is no or practically no sludge. Such effluent can be brought into line with government regulations. Alternatively, the effluent may be treated to remove any sludge that may be present using a clarifier, and may be returned to the effluent generating method or sent to other streams, for example, to cool towers, boilers to produce steam, heat exchangers, scrubbers, reactors, etc.

In one embodiment, the invention provides a packed reactor in a series of alternating layers. Alternating packing layers include a first packing layer of hollow elements and a second packing layer of porous support elements with pores of about 15-20 ppi. The hollow packing elements in the first layer may optionally be cylindrical packing. The void volume in the first packing layer may optionally be about 70-95%. In addition, the first layer may optionally be a monolayer of hollow packing elements. Alternatively, the first layer may have a thickness of up to about 10 packing elements. The porous support elements in the second layer may optionally be made of foam with a surface to volume ratio of about 35-210 ft ² / ft ³ . The foam may optionally have a void volume of about 15-25%. Optionally, the elements of the porous support of the second layer can be made of hydrophobic foam. Optionally, the elements of the porous support of the second layer can be made of polyurethane foam. In addition, it is not necessary that the elements of the porous support of the second layer have a surface to volume ratio of about 5-20 times greater than the surface to volume ratio of the hollow packing elements. It is not necessary that the second layer has a thickness of up to about 10 layers of square elements of the porous carrier.

In another embodiment, the invention provides a packed reactor containing a series of alternating layers of packing. Alternating packing layers include a first packing layer of hollow packing elements randomly packed into a layer with a thickness of up to about 10 packing elements, and a second packing layer of hydrophobic foam porous support elements with pores ranging in size from about 15-20 ppi. The second layer is also randomly packed to a thickness of up to about 10 elements of the porous support. In addition, the packing elements of the first layer and the elements of the porous support of the second layer are selected in shape so that the void volume in the reactor remains equal to about 50-65%. The hollow packing elements of the first layer may optionally be in the form of plastic cylinders. The void volume in the first packing layer may optionally be about 70-95%. The porous support elements in the second layer may optionally be made of foam with a surface to volume ratio of about 35-210 ft ² / ft ³ . Elements of the porous support of the second layer may optionally have a void volume of about 15-25%. Optionally, the elements of the porous support of the second layer can be made of polyurethane foam. It is not necessary that the elements of the porous support of the second layer have a surface to volume ratio of about 5-20 times greater than the surface to volume ratio of the hollow packing elements.

In yet another embodiment, the invention provides a packed reactor containing a series of alternating layers of packing. Alternating packing layers include a first packing layer of hollow packing elements randomly packed into a layer of up to about 10 packing elements and a second packing layer of hydrophobic foam porous carrier elements. The support elements have pores of about 15-20 ppi and are randomly packed to a thickness of up to about 10 elements of the porous support. In addition, the packing elements of the first layer are almost cylindrical in shape and the elements of the porous support of the second layer are almost rectilinear. The first packing layer optionally contains voids in a volume of about 70-95%, and in the second packing layer, the volume of voids is about 15-25%.

The following examples illustrate and represent the present invention, the scope of which is actually much larger. It should not be considered that the examples in one way or another limit the invention.

EXAMPLES

A series of experiments was carried out to assess the influence of the orientation of hollow packing elements and porous biomass carriers, i.e. made of polyurethane foam.

Example I

Rigid hollow cylinders (plastic) were obtained from Jaeger Products, Inc. under the trademark HiFlow. These hollow cylinders were used as hollow packing elements in biodegradation experiments. Biologically active elements were made of polyurethane foam (PUF) from Foamex, Inc., under the trademark SIF II. This foam contains 75 wt.% Polyols (about 40 wt.% Ethylene oxide and 60 wt.% Propylene oxide) and about 25-35 wt.% Toluene diisocyanate. The foam contained 15-20 pores per inch, and the pores were of different sizes.

Figure 5 illustrates three configurations of the used reactors. Porous PUF (110) biomass carriers and HiFlow (120) hollow packing elements were mixed in different ways to achieve a certain level of openness or the desired volume of voids in each bioreactor. The reactors were of the same volume (1 L), and each reactor contained the same number of hollow packing elements 120 and structures of the porous biomass carrier included in the biologically active elements 110.

Bioreactor 1 (49) consisted of two sections. The lower part was stuffed with hollow elements - 0.5-inch HiFlow cylinders and the upper part was stuffed with 0.5-inch cubes of polyurethane as active carriers of biomass.

Bioreactor 2 (50) consisted of randomly mixed porous biomass carriers 110 and hollow packing elements 120 randomly distributed throughout the bioreactor.

Bioreactor 3 (51) contained alternating layers of only hollow elements of packing 120 and only layers of porous carriers of biomass 110.

The same model wastewater was passed into these three bioreactors, which consisted of the following components in the following concentrations: sodium n-cocoyl-n-methyltaurate 100 mg / l; Igepal CO-630 (nonylphenol ethylene oxide) 100 mg / l; urea 1000 mg / l; creatinine 200 mg / l; caprolactam 20 mg / l; ethanol 50 mg / l; benzyl alcohol 20 mg / l and sodium dihydrogen phosphate 25 mg / l.

The reactors worked on the principle of direct-flow upward flow, i.e. and air and waste water moved from the bottom to the top of the reactor from the respective entry points (138 - gas, 130 - liquid). The reactor was aerated with compressed air (40 psi) through a porous glass diffuser 140 located at the bottom of each reactor 100. Using a gas flow regulator, aeration through the diffusers 140 was controlled at a level of 8-13 l / min. The same amount of air was supplied to each reactor. The aeration rate was determined on the basis of stoichiometry of the complete decomposition of substances oxidized by oxygen consumption (COD). The transfer efficiency (from air to water) of 8% is assumed. Wastewater was pumped to the bottom of each reactor with a Masterflex peristaltic pump. The flow rate of wastewater was regulated by changing the speed of the pump. Three bioreactors operated at hydraulic contact times of 48 hours, 24 hours, 18 hours and 12 hours each for a week at each hydraulic contact time. The amount of COD and urea removed from the incoming wastewater was determined in the effluent from the bioreactor 134.

Table I summarizes data on the removal of substances oxidized by the consumption of oxygen (COD) and urea from these wastewaters in three bioreactors.

All bioreactors were the same size and contained the same number of hollow packing elements and porous biomass carriers made of polyurethane foam. The only difference between the reactors was the packing distribution within the reactors. Bioreactor 1 (49) contained hollow packing elements and porous biomass carriers in two different sections. This packing configuration resulted in the lowest removal of COD and urea. Bioreactor 2 (50) contained hollow packing elements and porous biomass carriers randomly distributed throughout the reactor. This configuration showed increased activity in the removal of COD and urea compared with bioreactor 1 (49). It can be assumed that this is due to the improved distribution of air and water in the bioreactor. Bioreactor 3 (51) contained hollow packing elements and porous biomass carriers in alternating monolayers, and this bioreactor had the best activity in removing COD and urea.

The difference between the reactors in the removal of COD and urea is most pronounced at small hydraulic contact times (i.e., at higher flow rates) than at large hydraulic contact times (i.e., at lower flow rates). For the most cost-effective wastewater treatment, it is advisable to use shorter hydraulic contact times in bioreactors. Under such conditions, the advantage of the packing configuration in the bioreactor 3 according to an embodiment of the invention is more pronounced and confirms the superiority of the packing scheme of the reactor according to this invention.

Example II

Another series of experiments on the treatment of wastewater by biodegradation was carried out to compare the removal efficiency from the volume in the presence of a randomly dispersed system of hollow packing elements and porous carriers for biomass and a packing layer according to an embodiment of the present invention containing alternating layers of the same carriers and packing elements.

As shown in FIG. 6, four reactors were used in pairs. Each of the pairs 60 and 61 consisted of two reactors 100, 101 connected in series so that the effluent from the first reactor 100 served as feed for the next reactor 101. The efficiency of complete carbon removal (TOC) for each system was determined by the method of Example I . The control pair of reactors, consisting of two one-liter reactors connected in series 100, 101, was randomly filled with 0.5-inch HiFlow packing elements (120) and 0.5-inch SIF II (110) foam blocks, while the other row 61 was filled with packing, consisting of alternating layers of HiFlow 120 and polyurethane PUF blocks 110 (61).

In each pair, the reactors 100, 101 operated in a joint upflow mode. Process stream for processing enters the reactor 100 at the inlet and enters line 133, which feeds the reactor 101, feeding it to the bottom. The process stream flows upstream of reactor 101 and exits through outlet 134. Reactors 100, 101 are aerated with compressed air (40 psi) through a porous glass diffuser located at the bottom of each reactor. Using a gas regulator, aeration through diffusers was regulated at the level of 8-13 l / min. The same amount of air was supplied to each pair of reactors.

The treated wastewater was pumped to the bottom of the reactor 100 in each system 60, 61 using a Masterflex peristaltic pump. The flow of wastewater was regulated by changing the speed of the pump. Each pair of bioreactors 60, 61 worked at hydraulic contact times of 10 hours for a week. The amount of TOC removed from the feed wastewater was determined in the stream leaving the bioreactor through outlet 134.

Table II data on the removal of CBT from wastewater in two bioreactor systems.

Table II Bioreactor CBT in the exhaust stream (mg / l) Stand. deviation Dispersion Packing (60) 35 25 Layer Packing (61) fifteen 12

In the bioreactor system with layer-by-layer packing (61) according to an embodiment of the invention, a significantly lower level of TOC and with less fluctuations is observed in the effluent stream than in a bioreactor with random packing.

Although at least one option has been described in detail above, it should be emphasized that there are many options. It should be borne in mind that the exemplary embodiment or the options described here in no way limit the scope, applicability or configuration of the invention. Moreover, the above detailed description will serve as a convenient tool for specialists in this field to implement the described option or options. It should be understood that various changes in the functioning and arrangement of elements are possible if they do not deviate from the scope of the invention within the scope of the claimed formula and its acceptable equivalents.

Claims (10)

1. A packed reactor containing a series of alternating packing layers, the alternating layers comprising a first packing layer consisting of hollow packing elements and a second packing layer consisting of porous support elements (110) with microorganisms deposited on them, the ratio of surface to the volume of the porous support is greater than this ratio for hollow packing elements, with pores measuring 6-8 pores per cm. 2. The reactor according to claim 1, in which the hollow elements of the first layer of packing are cylindrical elements. 3. The reactor according to claim 1, in which the first packing layer contains voids comprising approximately 70-95%. 4. The reactor according to claim 1, in which the first layer contains an almost monolayer of hollow packing elements. 5. The reactor according to claim 1, in which the first layer is a layer with a thickness of up to about 10 packing elements. 6. The reactor according to claim 1, in which the elements of the porous carrier in the second layer consist of foam with a ratio of surface to volume of about 35-210 ft ² / ft ³ . 7. The reactor according to claim 1, in which the elements of the porous carrier in the second layer consist of foam with a void volume of approximately 15-25%. 8. The reactor according to claim 1, in which the elements of the porous carrier in the second layer consist of a hydrophobic porous foam. 9. The reactor according to claim 1, in which the elements of the porous carrier in the second layer consist of porous polyurethane foam. 10. The reactor according to claim 1, in which the elements of the porous carrier in the second layer consist of foam and are characterized by a ratio of surface to volume approximately 5-20 times greater than the ratio of surface to volume in hollow packing elements.

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